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Monday, March 15, 2010

We appreciate your interest and support! We will continue in our efforts to maximize the near-stock engine and fuel system package until we are satisfied we have achieved all it can deliver. Then we will move on to phase two in our quest to push the truck to 190 MPH.

Because we wanted to make some upgrades to our racer’s ’08 engine and because time was rapidly running out for getting it done in time to attend the August '09 Speed Week event, we opted to reduce the stress on ourselves and cancel out of all three 2009 Salt Flat events.

In a last minute decision, some of the guys and I decided to attend the August Speed Week event as spectators. That did it! Before we knew it, those go-fast flames had been rekindled. On the way home, we brainstormed about building an interim engine for the September and October 2009 events. Time was tight so this engine would not be able to use the planned-on upgrades for the race engine. Instead, it would be a more conventional build up of a standard engine: much more similar to we find in our everyday drivers. Then I learned that our engine machinist, Rich Eims of Joe’s Grinding in Yakima, was on vacation and would not be able to complete necessary machining operations in time to support our schedule.

The electronically controlled, high-pressure, common-rail diesel fuel systems of today render most owners lost when attempting to comprehend just what occurs under the hood. Cutting to the chase, not knowing what is and what is not considered normal operation of the Duramax can fuel owner paranoia and bring one to the misconceived notion that a new (and expensive) batch of fuel injectors are needed when, in fact, they are not.

It has not helped that GM historically has demonstrated the inability to produce a reliable diesel fuel injection system. Check that – its first foray into electronically controlled diesel injection pumps on the 6.5 turbo diesel marked that engine forever as unreliable and cantankerous despite the resourceful owners and technicians that have dug in and found reasonable solutions to make the 6.5 more reliable. I still deal with people from the other diesel camps – the Cummins and Powerstoke faithful – who believe that the Duramax is merely a refreshed version of the 6.5 with all its failings: failings that are naturally exaggerated by those who have a prejudice against the General. The common notion that the 6.5 turbo diesel has an unreliable fuel system tainted the Duramax somewhat, especially at the start.

In previous Lube Notes we looked at the role lubricants play in overcoming the effects of friction. In this installment, I want to examine one specialized type of lubricant: grease lube. Looking at previous civilizations, we can see that man has tried several methods to provide basic lubrication to load-bearing surfaces; axles have presented one of the most challenging applications. As far back as 1400 BC, mutton fat and beef tallow were used on chariot axles to reduce friction in order to allow for more speed and to slow down wear. One can only imagine the pressure on the maintenance men to make the chariot go faster and to avoid axles catching on fire from the continuous friction. While there is evidence of lime being added to these fats in order to make their lubricating properties last longer, few other improvements to the composition of grease are known to have been used until we reach the magic year of 1859.

What happened in 1859? Colonel Drake drilled the first ever oil well in Pennsylvania; since then, the world has not been the same. In petroleum oil, man found a lubricant that could be manipulated in a variety of ways to produce greases much superior to the lubricants that preceded them. In turn, more advanced and effective greases have been produced in recent decades with the advent of synthetic greases.

Last issue, Joel Paynton wrote about aftermarket power modifications on the Duramax diesel and their potential affects on your GM warranty. Shortly after, on August 4, 2009, GM posted Bulletin #08-06-04-006D which contained this statement:

Important: In order to process ANY driveability/engine/transmission/drivetrain WARRANTY CLAIM, you MUST photograph the required Tech 2® screen information BEFORE servicing or removing any engine/transmission/drivetrain components from the vehicle.

This had broad implications, requiring a technician to do all the groundwork to ensure there is no power program in the truck before doing any powertrain warranty work. It could be interpreted to mean that even minor and completely unrelated powertrain issues, for example, leaky seals, an electrical failure, a failed sensor and so on, would obligate the technician to investigate and document if there is a power program in the ECM. GM seemed to be launching an all-out campaign to find and stamp out anyone running aftermarket calibrations in their ECM.

My initial intention for the Jag was to put a Small-Block-Chevy (SBC) in it. Having had the opportunity to drive a number of different Jags, I must say that I have always enjoyed the Jaguar ride: it is an awesome vehicle to drive. My wife liked to call her ‘93 Jag Sex on Wheels. I don’t know that I would go quite that far in trying to communicate the thrill of driving one – but they are a great ride.

The electronics and power plants, however, have always left much to be desired. The V12 is notorious for dropped valves (which I think had been the case in our motor) and the Lucas wiring is way beyond quirky… leaving no doubt why a normal conversion path involves using a GM motor as the power plant. This SBC arrangement mates the awesome ride of a Jag with the reliability of a GM. That there is a lot of support available for such a project – it has been done often enough before – is a bonus.

Never one to go the normal route, I began looking at various engine options. One of my early considerations had been a GM diesel of some type. I initially shelved the idea due to weight, size and power issues. I have ultimately come back to the GM diesel for a number of reasons.

With a powerplant that only operates at 35% efficiency, losing three percent to diesel timing issues – a common occurrence – represents nearly 10% of available output... that is BIG. By itself, that three percent can reduce the speed of your truck on an extended grade enough so that the cooling system no longer receives sufficient air to fulfill the heat load rejection requirements of the cooling stack. On the other hand, gaining that three percent with optimum diesel timing can not only mean maintaining the power and speed that your truck needs to keep the cool air flowing... it can also mean that your engine actually sends less heat into the cooling system.

I have a confession to make: I am not a big fan of dynos. Torque curves on paper don’t excite me that much. Instead, I like to see a truck’s work performance in the real world. A vehicle that has been tested with a 15,000-pound trailer was not meant to be confined to a gerbil cage flexing its quadrupeds. If you were to extend that five-second WOT power level for two minutes, those curves would erode: a 300 HP truck optimized in a cool garage for those five seconds will often lose 25 to 75 HP on an sustained desert grade.